[src/trunk]: src/sys/fs/tmpfs tmpfs_statvfs: hold accounting lock, since tmpf...

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7a9ad7b5a55a
branches:  trunk
changeset: 755869:7a9ad7b5a55a
user:      rmind <rmind%NetBSD.org@localhost>
date:      Sat Jun 26 03:38:14 2010 +0000

description:
tmpfs_statvfs: hold accounting lock, since tmpfs_pages_avail() and
tmpfs_bytes_max() may fluctuate while in calculations.

diffstat:

 sys/fs/tmpfs/tmpfs_vfsops.c |  14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diffs (49 lines):

diff -r 7e571cd47014 -r 7a9ad7b5a55a sys/fs/tmpfs/tmpfs_vfsops.c
--- a/sys/fs/tmpfs/tmpfs_vfsops.c       Sat Jun 26 01:48:57 2010 +0000
+++ b/sys/fs/tmpfs/tmpfs_vfsops.c       Sat Jun 26 03:38:14 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tmpfs_vfsops.c,v 1.45 2010/06/22 18:32:08 rmind Exp $  */
+/*     $NetBSD: tmpfs_vfsops.c,v 1.46 2010/06/26 03:38:14 rmind Exp $  */
 
 /*
  * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.45 2010/06/22 18:32:08 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.46 2010/06/26 03:38:14 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -325,23 +325,27 @@
 static int
 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp)
 {
+       struct tmpfs_mount *tmp;
        fsfilcnt_t freenodes;
-       struct tmpfs_mount *tmp;
+       size_t avail;
 
        tmp = VFS_TO_TMPFS(mp);
 
        sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE;
 
+       mutex_enter(&tmp->tm_acc_lock);
+       avail =  tmpfs_pages_avail(tmp);
        sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT);
-       sbp->f_bavail = sbp->f_bfree = tmpfs_pages_avail(tmp);
+       sbp->f_bavail = sbp->f_bfree = avail;
        sbp->f_bresvd = 0;
 
        freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt,
-           tmpfs_pages_avail(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node));
+           avail * PAGE_SIZE / sizeof(struct tmpfs_node));
 
        sbp->f_files = tmp->tm_nodes_cnt + freenodes;
        sbp->f_favail = sbp->f_ffree = freenodes;
        sbp->f_fresvd = 0;
+       mutex_exit(&tmp->tm_acc_lock);
 
        copy_statvfs_info(sbp, mp);